O-alkyl,s,s-diaryl dithiophosphates



United States Patent US. Cl. 260-951 8 Claims ABSTRACT 0F THE DISCLOSURE O-(alkyl, alkenyl, alkynyl, and haloalkyl)-S,S-di(phenyl and mono and di-halo, nitro, alkyl and alkoxy substitutedphenyl)-dithiolphosphoric acid triesters which possess fungicidal properties.

The present invention relates to particular new S,S-diphenyl-dithiolphosphoric acid triesters having fungicidal properties, to compositions thereof with dispersible carrier vehicles, and to the preparation and use thereof.

French Patent No. 1,378,035 discloses (thiono) dithiolphosphoric acid diester monoamides of the general formula:

in which R and R may signify hydrogen atoms or alkyl oraryl radicals and R or R stand for the (inter alia) aryl radicals, while X is an oxygen or sulfur atom. According to the information given in the aforesaid French patent, these compounds are suitable for the control of plant pests and plant diseases.

It is an object of the present invention to provide particular new S,Sdiphenyl-dithiolphosphoric acid triesters which possess valuable fungicidal properties, to provide active compositions in the form of mixtures of such com pounds with solid and liquid dispersible carrier vehicles, to provide a process for producing such compounds, and to provide methods of using such compounds in a new way, especially for combating fungi.

Other and further objects of the present invention will become apparent from a study of the within specification and accompanying examples.

It has now been found in accordance with the present invention that the particular new S,S-dip'henyldithiolphosphoric acid triesters having the general formula:

"ice

good yields and with considerable purity by the process which comprises reacting phosphoric acid monoester dihalides having the general formula:

0 Hal Hal (Ila) in which R is the same as defined above and Hal is a halogen atom such as chloro, bromo, fluoro or iodo, especially chloro, with thiophenols having the general formula:

in which R and n are the same as defined above in the form of their salts or in the presence of acid binding agents.

The particular new S,S-diphenyldithiolphosphoric acid triesters of general Formula I above are distinguished by outstanding fungitoxic properties and, surprisingly, they are in this respect distinctly superior to the compound of analogous constitution and the same type of activity which are known from the aforesaid French patent.

The course of the reaction according to the instant invention is illustrated by the following equation:

0 H31 (ROI! ll ROP 2118-- Hal wherein R, R, Hal and n are the same as defined above.

As examples of the starting phosphoric acid monoester dihalides of general Formula Ila, there may be mentioned: 10-ethy1-, O-n-propyl-, O-isopropyL, O-n-butyl-, Oally1-, O-crotonyl-, O-propargyb, O-2-chloroethy1- and O-2,2,2-trichloroethylphosphoric acid monoester dichlorides. As examples of the starting thiophenols of general Formula Ilb, there may be mentioned: thiophenol, 2-, 3- and 4-chlorothiophenol, 4-isopropyl-thiophenol, 4-mothoxy-thiophenol, 4-nitro-thiophenol, 2-, 3- and 4-thiocresol, and Z-bromothio-para-cresol.

The phosphoric acid monoester dihalides usable as starting materials according to the present invention have already been described in the literature. They may be prepared according to known methods from the phosphorus oxyhalides by reaction with the corresponding alcohols, frequently without the concurrent use of acid acceptors. The crude products obtainable in this manner can in most cases be immediately further reacted for the purposes of the present invention without prior purification by distillation.

The process of the present invention is preferably carried out in the presence of solvents or diluents. As such, practically all inert organic solvents are suitable. However, particularly good results have been obtained with aliphatic and aromatic hydrocarbons (optionally chlorinated), for example methylene chloride, di-, triand tetrachloroethylene, chloroform, carbon tetrachloride, benzine, benzene, chlorobenzene, toluene and xylene; ethers, for

example diethyl and di-n-butyl ether, dioxan, tetrahydrofuran; aliphatic ketones and nitriles of low molecular weight, for example acetone, methylethyl ketone, methylisopropyl ketone, methylisobutyl ketone, acetonitrile and propionitrile; and low boiling aliphatic alcohols, for example methanol, ethanol and isopropanol; and the like.

As mentioned above, the reaction in accordance with the instant invention may be carried out in the presence of acid binding agents. The usual acid acceptors such as alkali metal (e.g. sodium, potassium, etc.) hydroxides, carbonates and alcoholates, and also tertiary organic bases, for example triethylamine, dimethyl aniline and pyridine, may be used as acid binding agents. Instead of working in the presence of acid binding agents, the salts, preferably alkali (e.g. sodium, potassium, etc.) or ammonium salts, of the thiophenols concerned may first be prepared and then reacted with the phosphoric acid monoester dihalides.

The production process of the present invention can be carried out successfully Within a wide range of temperatures. It is generally performed between 20 C. and the boiling point of the mixture, preferably between about and 100 C.

The reaction is preferably carried out under normal or atmospheric pressure, but it is also possible to work at increased or reduced pressure.

When carrying out the process in accordance with the invention, two mols of the thiophenol are generally used for each mol of the phosphoric acid monoester dihalide concerned; the thiophenol may, however, also be used in excess.

Moreover, the phosphoric acid monoester dihalide is expediently added dropwise, at the above mentioned temperatures and with stirring, to the solution or suspension of the thiophenol (or of the corresponding phenolate). External cooling of the mixture is often necessary, because the reaction generally proceeds with a more or less strong evolution of heat. Finally, it has proved expedient, after mixing the starting components, to stir the reaction mixture for an appreciable period (e.g. 1 to hours or overnight), optionally with moderate heating, in order to complete the reaction. In this case the products of the reaction are obtained in particularly good yields as well as with outstanding purity.

The working up of the reaction mixture may be effected according to methods which are known in principle by pouring the mixture into water, washing and drying the organic phase, distilling off the solvent and (as far as possible) fractional distillation of the residue under reduced pressure.

The particular new dithiolphosphoric acid triesters obtainable by the instant process are obtained either in the form of crystalline compounds with a sharp melting point which can easily be further purified by recrystallization from the customary solvents, or in the form of colorless to yellow oils some of which can be distilled under greatly reduced pressure without decomposition. If this is not possible, the compounds obtainable according to the invention may, for the purpose of purification, be partially distilled, i.e. freed from the last volatile impurities by heating to slightly to moderately elevated temperatures for an appreciable period and under reduced pressure.

By means of the present process, inter alia, the following compounds can be obtained: O-ethyl-, O-n-propyl and O-n-butyl-S, S-diphenyl-; O-ethyl-, O-n-propyland Q-n-butyl-S,S-di(2 or 4-methylphenyl)-; O-ethyland O- isopropyl-S,S-di(4-chlorophenyl); O-ethyl-S,S-di(4-methoxyphenyl)-, O-allyl-S,S-diphenyl-, O-ethyl-S,S-di(2,4-dichlorophenyl)-, O ethyl-S,S-di(4-nitrophenyl)-, O-isopropyl-S,S-diphenyland O isopropyl-S,S-di-(Z-methylphenyl)- -dithiolphosphoric acid esters.

As already mentioned, the particular new dithiolphosphoric acid triesters of the present invention are strongly fungitoxic to a number of fungoid pathogenic agents. By reason of this fact, as well as in view of their low toxicity towards warm-blooded animals, they are particularly suitable for the control of undesirable plant growth, their good compatibility with higher plant particularly favoring their use against fungus diseases. The particular new compounds of the invention can be used as fungitoxic agents in plant protection against fungi of the most widely varied classes, e.g. Archimycetes, Phycomycetes, Ascomycetes, Basidiomycetes and Fungi imperfecti.

However, the compounds of the invention have yielded particularly good results in the control of diseases of rice, since they possess an excellent protective and curative action, for instance, against Piricularia oryzae in rice.

Thus, the new compounds of the instant invention can be used as fungicides, either alone or in admixture with solid or liquid carriers or diluents.

The active compounds according to the instant invention can be utilized, if desired, in the form of the usual formulations or compositions with dispersible carrier vehicles, such as solutions, emulsions, suspensions, emulsifiable concentrates, spray powders, pastes, soluble powders, dusting agents, granulates, etc. These are prepared in known manner, for instance by extending the active agents with dispersible liquid diluent carriers and/or dispersible solid carriers optionally with the use of carrier vehicle assistants, e.g., surface-active agents, including emulsifying agents and/ or dispersing agents, whereby, for example, in the case where Water is used as diluent, organic solvents may be added as auxiliary solvents (cf. Agricultural Chemicals, March 1960, pages 35-38). The following may be chiefly considered for use as carrier vehicles for this purpose: dispersible liquid diluent carriers, such as aromatic hydrocarbons (for instance, benzene, toluene, xylene, etc.), halogenated, especially chlorinated, aromatic hydrocarbons (for instance, chlorobenzenes) parafiins (for instance, petroleum fractions), chlorinated aliphatic hydrocarbons (for instance, methylene chloride, etc.), alcohols (for instance, methanol, ethanol, propanol, butanol etc.), amines (for instance, ethanolamine, etc.), amides (for instance, dimethyl formarnide, etc.), sulfoxides (for instance, dimethyl sulfoxide, etc.), ketones (for instance, acetone, etc.), and water; as well as dispersible finely divided solid carriers, such as ground natural minerals (for instance, kaolins, alumina, silica, chalk, i.e., calcium carbonate, talc, kieselguhr, etc.) and ground Synthetic minerals (for instance, highly dispersed silicic acid, silicates, e.g., alkali silicates, etc.); where as the following may be chiefly considered for use as carrier vehicle assistants, e.g., surface-active agents, for this purpose: emulsifying agents, such as non-ionic and anionic emulsifying agents (for instance polyethylene oxide esters of fatty acids, polyethylene oxide' ethers of fatty alcohols, alkyl sulfonates, aryl sulfonates, etc., and especially alkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc.); and dispersing agents, such as lignin, sulfite waste liquors, methyl cellulose, etc.

As will be appreciated by the artisan, the active compounds according to the instant invention may be present in such formulations or compositions in the form of mixtures with one another and with other known active substances, if desired.

The substances according to the invention may be employed by themselves as the artisan will appreciate, in the form of their compositions with solid or liquid dispersible carrier vehicles or other known compatible active agents, or in the form of particular dosage preparations for specific applictaion made therefrom, such as solutions, emulsions, suspensions, powders, pastes, and granulates which are thus ready for use.

As concerns commercially marketed preparations, these generally contemplate carrier composition mixtures in which the active compound is present in an amount substantially between about 01-95% by weight, and preferably 0.5% by weight, of the mixture, whereas carrier composition mixtures suitable for direct application or field application generally contemplate those in which the active compound is present in an amount substantially between about 0.001 and 0.2% by weight, and preferably 0.0001 and by weight, of the mixture. Thus, the present invention contemplates over-all compositions which comprise mixtures of a dispersible carrier vehicle, such as l) a dispersible carrier solid, or (2) a dispersible carrier liquid preferably including a carrier vehicle assistant, e.g., surface-active agent, such as an emulsifying agent and/or a dispersing agent, and an amount of the active compound which is effective for the purpose in question and which is generally between about 0.0001 and 95 by weight, and preferably 0.001 and 20% by weight of the mixture.

Furthermore, the present invention contemplates methods of selectively controlling and combating fungi, which comprise applying to at least one of (a) such fungi and (b) their habitat, a fungicidally effective amount of the particular compound of the invention alone or together with a carrier vehicle as noted above. The instant formulations or compositions are applied in the usual manner, for example, by spraying, atomizing, vaporizing, scattering, dusting, watering, sprinkling, pouring, and the like.

In particular, the concentration of the active compound of the invention which is utilized with the carrier vehicle will depend upon the intended application, as the artisan will appreciate. In special cases, however, it is possible to go above or to go below such range of concentration, e.g., as aforesaid utilizing a broad range of 0.0001 and 95% by weight of the mixture.

The outstanding fungitoxic action of the S,Sdiphenyldithiolphosphoric acid triesters of the present invention, as well as their distinct superiority compared with prior art products of analogous structure, can be seen from the following experimental results set forth by way of illustration and not limitation:

EXAMPLE 1 Piricularia test: Liquid preparation of active substance 6 Solvent: 1 part by weight acetone Dispersing agent: 0.05 part by weight sodium oleate Other additive: 0.2 part by weight gelatin Water: 98.71 parts by weight H O.

The amount of the particular active compound required for the desired final concentration of such active compound in the spray liquor is mixed with the stated amount of solvent and the concentrate obtained diluted with the stated amount of water containing the stated dispersing agent and other additive.

Thirty rice plants, which are about 14 days old, are sprayed with the above prepared spray liquor until dripping Wet. The plants remain in a greenhouse at a temperature of 22 to 24 C., and at a relative atmospheric humidity of about until dry, They are then inoculated with an aqueous suspension of 100,000 to 200,000 spores/ ml. of Piricularia oryzae and placed in a chamber at 2426 C. and at relative atmospheric humidity of 100%.

Five days after inoculation, the degree of infestation of all the leaves of the treated plants which were present at the time of inoculation is determined as a percentage of the untreated but also inoculated control plants. 0% means that no infestation occurred and 100% that the infestation is exactly the same as that of the control plants.

Test for curative action In the test just described using a liquid preparation of the active compound, besides the protective action, the curative action of the particular active compounds may also be determined. The test for curative action varies in certain points from the test procedure described above which only gives an indication of the protective effect. Specifically, in determining the curative effect, the particular active compounds are applied, not before inoculation, but 16 hours after inoculation. Substances which exhibit an action when the test is carried out in the latter manner are capable of destroying the fungus after the infection and thereby exercise a curative action.

The active compounds, their concentrations and the results obtained can be seen from the following Table 1:

TABLE 1.PIRICULARIA TEST (Liquid Preparation of the Active Compound) Infestation expressed as percentage of the infestation of the untreated control with an active compound concentration of (percent) Active Compound (Constitution) 0.05 0.025 0.01 0.005 0.001

0 ll pr. 0 0 0 0 (III) n-C H OP S 0111. 0 O 11 0 pr. 0 0 5 14 (IV) Ii-C4I'I90-"P S our. 0 0

(I) I (v) CzH5OP(SOHa) p 0 2 s3 O [I pr. 0 0 0 75 (VI) C H5O-P S our. 0 0

l CH3 0 ll pr. 0 0 15 v11 l1-C3H70P s cur. 25

| CH 2 (if (VIII) is0-C3H70-P(SCl) pr 0 0 r5 O pr. 0 0 0 13 58 (IX) unto-P s our. 0 a

TABLE 1.C0ntinued Infestation expressed as percentage of the infestation of the untreated control with an active compound concentration of (percent) Active Compound (Constitution) 0.05 0.025 0.01 0.005 0.001

H (X) Tl-C4H0O'P S pr. 0 75 0 pr. 0 0 o 0 (XI) iso-C3H1OP (S cur. 0 25 (XII) CzHO-P (S O CH3) pr. 0 O 28 75 0 pr. 0 (A8.) (CzHs) 2NP S- -CH3 CHI. 96

(known comparative preparation from French Patent 1,378,035)

pr.=protcctive action. cur.=curative action.

EXAMPLE 2 O M Q) 110 grams (1 mol) of thiophenol are dissolved in 800 cc. of benzene. To the resulting solution is added, with stirring, a sodium methylate solution which contains 1 mol of sodium in solution. 82 grams (0.5 mol) of O-ethylphosphoric acid ester dichloride are then added dropwise to the reaction mixture at 5 to C. with further stirring. The reaction mixture is kept at the stated temperature for a further three hours, poured into 400 cc, of ice water and then washed twice with 300 cc. of water in each case. The benzene solution is then dried over anhydrous sodium sulfate. During the ensuing fractional distillation, after evaporation of the solvent, 108 grams (70% of the theoretical amount) of O-ethyl-S,S-diphenyl-dithiol-phosphoric acid ester with a boiling point of 154 C./0.01 mm. Hg are obtained.

EXAMPLE 3 (a) A solution of 44 grams (0.4 mol) of thiophenol in 100 cc. of benzene is neutralized with a sodium methylate solution containing 0.4 mol of sodium. After distilling off the solvent, the sodium thiophenolate which remains is suspended in 200 cc. of benzene and to this suspension there are added dropwise, at 0 to 5 C., 35.4 grams (0.2 mol) of O-n-propylphosphoric acid ester dichloride. The reaction mixture is then stirred for a further 3 hours at C., washed With water after cooling to room temperature, and dried over anhydrous sodium sulfate, The solvent is evaporated under reduced pressure and, as residue, 28 grams (43.3% of the theoretical amount) of O-npropyl-S,S-diphenyldithiolphosphoric acid ester are obtained.

Analysis.-Calculated: P, 9.58%; S, 19.76%. Found: P, 9.35%; S, 19.70%.

(b) 220 grams (2.0 mol) of thiophenol are converted into the corresponding sodium thiophenolate in the manner described in Example 3(a). The dry salt is suspended in 500 cc. of acetonitrile, and to this suspension 177 grams (1.0 mol) of O-n-propylphosphoric acid ester dichloride are added dropwise at 0 to 10 C. The reaction proceeds with evolution of heat. The reaction mixture is further stirred for some time at room temperature and then poured into water. The oil which is separated is dissolved in bezene and the benzene solution is washed with water and dried over anhydrous sodium sulfate. The solvent is then distilled off under reduced pressure. The last volatile portions are removed at bath temperature of C. and 1.5 mm. Hg, and the resulting O-n-propyl- S.S-diphenyl-dithiophosphoric acid ester is obtained in the form of a yellow oil. The yield is 221 grams (68% of the theoretical amount).

Analysis.Calculated: P, 9.58%; S, 19.76%. Found: P, 9.70%; S, 19.90%.

EXAMPLE 4 grams (1.0 mole) of thiophenol are converted in the usual manner into the sodium salt, as noted in Example 3. The dry lhiophenolate is suspended in 500 cc. of acetonitrile and the suspension is reacted with 95.5 grams of O-n-butylphosphoric acid ester dichloride in the manner described in Example 3(b). The reaction mixture is then stirred overnight at room temperature. The separated oil is dissolved in benzene after the mixture has been poured into water, and the benzene solution is washed with water until there is a neutral reaction and then it is dried. After evaporation of the solvent and removal of all volatile portions at a bath temperature of C. and a pressure of 1 mm. Hg, 120.5 grams (71.3% of the theoretical amount) of O-n-butyl-S,S- diphenyl-dithiolphosphoric acid ester are obtained as a pale yellow oil with a refractive index 11 of 1.5965.

Analysis.--Calculated: P, 9.18%; S, 18.94%. Found: P, 9.30%; S, 19.30%.

The following compounds can be prepared by methods analogous to the method described above using correstarting maphenol in 600 cc. of benzene is added 1 mol of sodium methylate. 89 grams of O-iso-propylphosphoric acid ester Yield Physical properties (percent of (Refractive Index Constitution the theory) or Melting Point) it v' oznior(s-om) 67 my 1.6061.

2 i W Guano-1 6G) 5s m, 1.6078.

2 l CHa i (VII) n-CgHq0P(S-( 67 mm 1.5993. 2 CH3 if (X) I1-C4HDO-P(S) 71 in, 1.5860.

2 l CH3 it (XII) C2H50P(SOCH3) 68.2 no 1.6152.

2 i (XIII) n-C3H1OP(S0CH 73.0 w 1.6088.

2 i (XIV) iSo-CaHrO-P S 79.6 'llr) 1.5946.

(3H3 2 i (XI) iso-C3H1OP (s 69.2 mm 1.6178.

2 ll (XV) ClCH2CH2-O-P(S) 71.9 71D 1.6281.

2 i (XVI) ClCH2-CH2-O-P S 42.9 116 1.6160.

1 CH3 2 i (XVII) ClaCCH2O-P S0 56.2 Melting point: I 90 to 92 0. CH3 2 EXAMPLES dichloride are then added dropWise :at to C., with stirring, after Which the reaction mixture is stirred C H 0 E 01) for a further 2 hours at the temperature stated and then 2 5 2 (XVIII) poured into 400 cc. of ice Water. After the benzene 145 grams (1 mol) of 4-chlorothiophenol are dissolved in 400 cc. of benzene. To this solution is added, With stirring, a sodium ethylate solution which contains 1 mol of sodium. Then, with further stirring, 82 grams (0.5 mol) of O-ethylphosphoric acid ester dichloride are added dropwise to the reaction mixture at 10 to 15 C. The reaction mixture is stirred for a further 2 hours at the temperature stated and then poured into 300 cc. of ice Water. The benzene solution is washed once more With Water and dried over anhydrous sodium sulfate. After the solvent has been distilled off, an oily, crude product is obtained as residue which solidifies very rapidly in crystalline form. 105 grams of the theoretical amount) of O ethyl-S,S-bis (4-chloro-phenyl) -dithiolphosphoric acid ester With a melting point of 71 C. are isolated.

EXAMPLE 6 To a solution of 145 grams (1 mol) of 4-chlorothiosolution has been Washed several times With water it is dried over anhydrous sodium sulfate and, finally, the solvent is distilled off. 123 grams (63% of the theoretical amount) of O-iso-propyl-S,S-bis(4-chlorophenyl)dithiolphosphoric acid ester with a melting point of 52/ C. are obtained.

EXAMPLE 7' f 021150-1 SQ-NOz) (XIX) 1 1 EXAMPLE 8 To a solution of 55 grams (0.5 mol) of thiophenol in 400 cc. of ethanol which contains 0.5 mol of sodium are added dropwise 40.75 grams (0.25 mol) of O-ethylphosphoric acid ester dichloride at 0 to C., and the mixture is then stirred overnight at room temperature. The reaction mixture is then poured into water, the separated oil is dissolved in benzene, the benzene solution is washed with water until there is a neutral reaction, and the organic phase is then dried over anhydrous sodium sulfate. After evaporation of the solvent there remain 51.5 grams (60.9% of the theoretical amount) of O-ethyl-S,S-diphenyl-dithiophosphoric acid ester which is identical to the compound of the same constitution which is obtainable according to Example 2.

EXAMPLE 9 55 grams (0.5 mol) of thiophenol are dissolved together with 56 grams (0.55 mol) of anhydrous triethylamine in 400 cc. of benzene. 44 grams (0.25 mol) of O-n-propylphosphoric acid ester dichloride are added dropwise to this solution at 0 to 10 C. The ensuing reaction proceeds exothermically. After the mixture has been stirred for a short time at room temperature, the precipitated triethylammonium hydrochloride is filtered off, the filtrate is washed with water, and the organic phase is dried and concentrated by evaporation. There remain as residue 56 grams (65.9% of the theoretical amount) of O-n-propyl-S,S-diphenyldithiolphosphoric acid ester. The compound is identical to that obtainable according to Example 3.

EXAMPLE 10 In the same way, in accordance With the procedure of Example 2, using corresponding molar amounts of the following starting materials:

(a) O-crotonylphosphoric acid ester dichloride (i.e. O-'yallylphosphoric acid ester dichloride) and 3-bromo-5- fiuorothiophenol-sodium;

(b) O-propargylphosphoric acid ester dichloride (i.e. O-

prop-2-yn-1-ylphosphoric acid ester dichloride) and 2-tert.-butoxy-thiophenol-sodium;

(c) O-fiuoromethyl-phosphoric acid ester dichloride and 4-isopropyl-thiophenol-sodium; and

(d) O-(4-bromo-n-butyl)-phosphoric acid ester dichloride and 2,4-dichloro-thiophenol-sodium;

(III) the respective final products are obtained:

(a) O-crotonyl-S,S-bis(3 bromo-S-fluoro phenyl)- dithiolphosphoric acid ester;

(b) O-propargyl-S,S-bis(2tert.-butoxy phenyl) dithiolphosphoric acid ester;

(0') O-fluoromethyl-S,S bis(4 isopropylphenyl) dithiolphosphoric acid ester; and

(d) O-(4-bromo-n butyl)S,S bis(2,4 dichlorophenyl)-dithiolphosphoric acid ester.

Advantageously, in accordance with the present invention, in the foregoing formulae:

R represents straight or branched chain alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.- butyl, tert.-butyl, pentyl, i.e. n-amyl, isoamyl, hexyl, and the like, and especially alkyl having 1-6 carbon atoms; or alkenyl such as vinyl, a, [3- and -allyl (i.e. crotonyl), l-, 2- and 3-butenyl, and the like, and especially alkenyl having 2-4 carbon atoms, and most especially crotonyl; or alkynyl such as ethynyl, land 2-propynyl, 1-, 2- and 3-butynyl, and the like, and especially alkynyl having 2-4 carbon atoms, and most especially propargyl; or haloalkyl such as mono-, di-, triand poly- -chloro-, -bromo-, -fiuoroand -iodoas well as mixed di-, triand poly- -chloro-, -bromo-, -fiuoroand -iodo-substituted methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec.-butyl, tert.-butyl, amyl, hexyl, and the like, especially haloalkyl having 1-6 carbon atoms, and most especially mono-, diand tri-chloro substituted methyl to hexyl inclusive including 2-chloroethyl, 2,2,2-trichlorethyl, and the like;

R represents halogen such as chloro, bromo, fluoro and iodo, especially chloro, bromo and fluoro, and most especially chloro; or nitro; or lower alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.-butyl, tert.-butyl, and the like, especially alkyl having 1-4 carbon atoms, and most especially methyl; or lower alkoxy such as methoxy, ethoxy, n-propoxy, isopropoxy, nbutoxy, isobutoxy, sec.-butoxy, tert.-butoxy, and the like, especially alkoxy having 14 carbon atoms, and most especially methoxy; and

n is a whole number from 0 to 2, especially 0-1.

All of the foregoing compounds in accordance with the present invention possess the desired strong fungicidal properties, with regard to a broad spectrum of activity, enabling such compounds with a concomitantly low toxicity toward warm-blooded creatures and corresponding favorable compatibility with higher plants to be used more effectively to control and/or eliminate fungi by application of such compounds to the fungi and/ or their habitat.

It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention.

What is claimed is:

1. S,S-diphenyl-dithiolphosphoric acid triester having the formula in which R is selected from the group consisting of alkyl having 1-6 carbon atoms, and R is selected from the group consisting of 2-chloro, 2- and 4-alkyl having 1-4 carbon atoms and 4-alkoxy having 1-4 carbon atoms, and n is a number from O to 1.

2. Triester according to claim 1 wherein R is selected from the group consisting of alkyl having 1-4 carbon atoms and R is selected from the group consisting of 2- chloro, Z-methyl, 4-methyl and 4-methoxy, and n is a number from 0 to 1.

3. Triester according to claim 1 wherein such compound is O-n-propyl-S,S-diphenyl-dithiolphosphoric acid ester having the formula:

4. Triester according to claim 1 wherein such compound is O-n-butyl-S,S-diphenyl-dithiolphosphoric acid ester having the formula:

5. Triester according to claim 1 wherein such compound is O-ethyl-S,S-bis(4 methylphenyl)-dithiolphosphoric acid ester having the formula:

7. Triester according to claim 1 wherein such compound is O-ethy1-S,S-bis(4 methoxyphenyl)-dithio1ph0sphoric acid ester having the formula:

8. Triester according to claim 1, wherein such compound is O-ethyl-S,S-diphenyl-dithiolphosphoric acid ester having the formula 1 4 References Cited UNITED STATES PATENTS 3,081,329 3/1963 Vegter 260-954 3,261,804 7/1966 Graham 260-954 XR FOREIGN PATENTS 1,255,792 1/1961 France.

CHARLES B. PARKER, Primary Examiner A. H. SUTTO, Assistant Examiner US. Cl. X.R. 

